The rotating magnetic field induces an ac voltage in the stator windings (coil ). The rotor’s magnetic field is produced by the neodymium magnet sphere. The permanent magnet field is constant and the terminal voltage varies directly with the speed of the dc motor. This is an AC electric generator which lights up led bulbs 7 W 230 V. The generator is composed of a coil without core – copper wires, a magnet (neodymium sphere) , a small dc motor, a metal screw pot case, a plastic holder and a battery.